The Study On The Expression Of Aurora-A In Human Brain Astrocytomas And The Relationship Between The Expression And The Clinical Pathognomonic Feature

Objective:Recent study shows that the formation of tumor is correlated to the abnormal ampification of centrosome;the formation of heteroploid;the instabale of chromosome which cause oncogene activation or anti-oncogene inactivation.Serine / threonine kinasel5(Aurora-A) is close related to the abnormal ampification of centrosome and malignant transformation,the over-expression of Aurora-A is related to the prognosis of some tumors.And it has been a target to treat pancreatic carcinoma. Many numerical data intema and abroad show that Aurora-A was over-expression in many solid tumor.Zhangjian et al detected the expression of Aurora-A in 62 cases gliomas only by immunohistochemical staining,the result showed that it was over-expression in glioma.We will detect the expression of Aurora-A in astrocytomas and non-tumor brain tissues by immunohistochemical staining and western blotting to approve the expression of Aurora-A in gliomas and to approach the relationship between the malignancy degree of astrocytomas and the clinical pathognomonic feature and Aurora-A,to find a new target to treat astrocytomas for clinic.Methods:(1) Thirty-three formalin-fixed,paraffin-embedded astrocytomas were obtained from the Department of Pathology of the First Affiliated Hospital of Anhui Medical University during the year of 2003 and 2007.Twenty normal brain tissues (non-tumor brain tissues) were obtained as normal control from surgical resections of trauma patients,for whom a partial resection of normal brain tissue was required as decompression treatment for their severe head injuries to reduce increased intracranial pressure.The SP immunohistochemical staining method was used to detect the expression of Aurora-A in 33 cases of human astrocytomas of various pathological grades and 20 cases of non-tumor brain tissue samples.To observe the expression of Aurora-A in astrocytomas of various pathological grades and non-tumor brain tissue samples(2) Twenty fresh tumor tissues and twenty fresh normal brain tissues were collected from the First Affiliated Hospital of Anhui Medical University during the operation of neurosurgery.All tissues were diagnosised as astrocytomas or non-tumor tissues by HE stainning.The expression of Aurora-A was examined by Western blotting assay in 20 frozen specimens of human brain astrocytomas and 20 non-tumor brain tissues.Results:(1) The positive percentage of the expression of Aurora-A by immunohistochemistry in gradeⅠ+ⅡandⅢ+Ⅳastrocytomas were 35.7%and 73.7%respectively,and no expression of Aurora-A was detected in normal brain tissue. There was a significant difference between brain astrocytomas and normal brain tissue (P＜0.01).The expression of Aurora-A was significantly correlated with histopathological grade(P＜0.05).(2) The level of Aurora-A detected by Western blotting in high-grade astrocytomas tissues is higher than in low-grade ones,and the total positive percentage is 100%.No expression of Aurora-A was detected in normal brain tissue.(3)The total positive percentage of the expression of Aurora-A by immunohistochemistry in 33 cases of astrocytomas were 57.6%;In 10 non-tumor brain tissue samples,no expression of Aurora-A was detected.There were statistically significant between astrocytomas and non-tumor brain tissue samples(P＜0.05).(4) The correlation between the increasing grade and Aurora-A PLI values were statistically significant.However,no correlation was detected between the age and sex of the patient and Aurora-A.The expression of Aurora-A proteins were significantly different between low-grade and high-grade astrocytomas,the expression of high-grade astrocytomas is higher than that of low-grade ones(P＜0.05). Conclusions:(1) The over-expression of Aurora-A was associated with the proliferating activity in human brain astrocytomas.Aurora-A gene may play an important role in the malignant progression in astrocytomas.(2) Aurora-A,a tumor marker may be used to evaluate the tumor grade and to asses the malignancy in human astrocytomas.